TCP/IP Socket Connection does not send anymore

Networking Solutions Question
1

Hi there,

I have a RUT906 and two client devices: The first client is a “ArduSimple RTK 3B incl. a NTRIP-Plugin” [1] and the second one is my notebook (Windows11). Bot clients are connection via LAN cables to the router. The RTK ist configured with the ip 192.168.1.3, the router on 192.168.1.1 and my notebook on 192.168.1.25. A Java-Service is running on my notebook and connects to an offered port on the RTK. The result is, that I can receive ASCII line-based data from the RTK with a frequency of 1Hz. This scenario runs very cleanly for a long time.

After an unspecific time range (could be between minutes and hours), the TCP/IP socket connection is still active/valid (confirmed by the resource monitor at my notebook), but it seems, that no sentences are received by the notebook anymore. There are no software-based exceptions at all. I have to kill and reconnect the socket connection to receive new data.

We have exchanged the router to a RUT951 and instead of the Java-Service we have used Putty. Even with these changes, we have the same behaviour of a “suddenly non sending connection” after an unspecific time.

Both, RUT906 and RUT951 have a standard configuration and were just updated by the latest firmware. There were no changes of the configuration at all.

If we replace the router with an unmanaged switch (e.g. netgear gs105), this behaviour does not occur and the socket connection runs for days.

Does anyone have any advice why this behaviour happens, and how I can avoid it? Or does anyone have similar issues?

Thanks

[1] simpleRTK3B Pro (Septentrio Mosaic X5) Tripleband-RTK-Karte - ArduSimple

& https://www.ardusimple.com/product/ethernet-ntrip-master

2

Greetings,

Could you please navigate to Network → Firewall → Settings and disable Software Flow Offloading? After doing so, please test again and let me know if the issue still occurs.

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Do you have static lease configured for the devices?

Best Regards,
Justinas

4

Hi there,

Thanks for your help. I have deactivated “Software Flow Offloading” and will test the behaviour. With the missbehaviour this issue occur approx. 4 times a day without any specific pattern. I will run this scenario with the new setting for a few days and let your know.

All components in the network (ca. 10) have static ip addresses. But there are not explicit configuration/rules set in the router.

Bests

Alex

5

So, here is a small update of the last days:

Before I have deactived this option, I had in average 4 issues per day.

Since 20/03/2026 I have deactivated it. In the last 6-7 there were just 6 issues in total, which means approx. 1 issue per day. I think the deactivation of this option optimized the situation - maybe these 6 issues had other causes.

6

Greetings,

Apologies for the delayed response.

Do you still require additional support, or have the issues been resolved?

Best Regards,
Justinas

7

Well, the problems have been reduced, like I wrote above.

But maybe the remaining issues are based on other (network) problems.

So, I think the ticket could be closed.

Thank you.